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7.01.2006

In recent years, scientific breakthroughs have opened up possibilities of revolutionary medical treatment that hold promise for treating a variety of medical conditions. But, just as these new technologies raise hopes for cures, they also raise complicated ethical concerns as well. One of these new technologies involves the research of embryonic stem cells, which over the past couple of years has been thrust into the national spotlight and hotly debated on both sides. Supporters of embryonic stem cell research point to it as the source of potential cures for devastating medical conditions such as Alzheimer’s Disease, Parkinson’s Disease, multiple sclerosis, and severe spinal cord injuries. Those opposed to embryonic stem cell research believe that no potential medical advancement can justify the destruction of human embryos. While developing cures to these severe medical conditions would potentially be a wonderful benefit to the lives of millions, it does not justify the termination of human embryos, especially considering the possibility of alternative measures which could be equally effective without damaging or destroying anyone.

In order to understand the debate over stem cell research, it is first necessary to understand a little bit about stem cells themselves. In simple terms, stem cells are basically “blank cells that potentially can be turned into any type of body tissue”.1 When stem cells divide, one of the resulting cells becomes a new, more specialized type of cell, while the other becomes an exact copy of the original stem cell, and replaces it. Embryonic stem cells are the very earliest stem cells which derive immediately from the fertilized egg. All of the different tissues of the body develop out of these first few stem cells, which are for this reason considered to be “totipotent” —totally potent.2 As the process of cell division continues, molecular signals begin to turn genetic switches on and off within the stem cells, causing the “daughter” cells from the successive divisions to be more and more specialized in function and thus, to gradually lose their potential for becoming any type of cell.3 This cell differentiation and specialization lead eventually to all of the different specialized cells of the body, as well as the different populations of “adult” stem cells within the body. Adult stem cells are those which have already gone partially down the road to specialization and have lost some of their potential for creating a wide range of cells. For example, all of the cells of the brain derive from a population of neural stem cells. Each time one of these neural stem cells divides, it produces a brain cell and a copy of itself. Scientists are uncertain as to just how many of these adult stem cell populations, each of which is responsible for forming a different subset of adult tissues, exist.2

While scientists have understood the existence of embryonic stem cells for some time, they have only recently become aware of their potential medical applications. About fifteen years ago, scientists discovered that they could disrupt the normal connections of the fertilized egg, causing the cells to “fall apart into a single cell suspension that could be maintained in culture.”2 These cells, no longer part of any developing embryo, continue to divide indefinitely in culture, and are termed embryonic stem cell “lines.” These stem cell lines can very quickly produce vast numbers of cells. However, in culture, without direction from any molecular blueprint, they produce specialized cells haphazardly, forming teratomas, chaotic lumps of tissue comprised of a combination of adult cell types such as skin, bone, and muscle. This discovery would have been unimpressive, had it not also been discovered soon after that these same stem cell lines could produce mature cell types in culture in an organized manner if provided with the proper type of molecular signal. Discovering the exact signals that initiate the formation of specific cell types has been a difficult and painstaking process, and is still ongoing. Despite this, the scientific community remains excited about the cultured cells’ ability to rapidly produce enormous numbers of cells because it is widely believed that cultured embryonic stem cells would still be totipotent, and would be able to produce all of the various mature cell types in the body, if only given the proper molecular signals.2

The potential medical value of being able to induce the development of specific types of mature cells is profound. Scientists predict that stem cells could aid in the treatment of a plethora of diseases and medical conditions, including Parkinson’s Disease, Alzheimer’s Disease, multiple sclerosis, diabetes, heart disease, severe spinal cord injuries, and others. Although the different treatments would be very complicated in practice, they are very simple and similar in theory. Basically, the doctor would take a stem cell, use the proper molecular signal to convert it into a specific type of adult cell, and inject it into the damaged area where the converted stem cells could then help to repair the damaged tissues. Whether replacing malfunctioning brain cells that cause Parkinson’s Disease, damaged cells in the spine which cause paralysis, or heart cells damaged by a heart attack, treatment with stem cells could revolutionize medical practice.1

From the amount of hype and excitement surrounding embryonic stem cell research, one might think that these stem cell replacement procedures were commonplace, and that many are already well on their way to a cure. However, Elizabeth Cohen, a medical correspondent for CNN emphasizes, “Let’s make one thing clear: stem cells at this point have not helped a single person,”1 and Maureen L. Condic, Assistant Professor of Neurobiology and Anatomy at the University of Utah suggests that the amazing medical advances hoped for by embryonic stem cell researchers are by no means a sure thing.2 Condic proposes three scientific arguments against the use of embryonic stem cells as a treatment for injury or disease. In the first place, there are serious immunological issues involved whenever cells generated by one human being are placed into the body of another. Just as problems arise when a person receives an organ transplant, so they would with the injection of stem cells produced outside of that person’s body. Eventually, such transplanted tissues and cells are targeted and destroyed by the subject’s immune system, unless the transplanted material is of a perfect genetic match that only an identical twin can provide. Condic says that “stem cell transplants…would not buy you a ‘cure’, they would merely buy you time,” as eventually, the supposed miracle-working stem cells would be attacked by the patient’s immune system. Scientists have proposed some solutions to the problem, but these, according to Condic, at this stage are still scientifically unrealistic, and thus, no solution at all. The second problem with the use of embryonic stem cells arises from the difficulty in discovering the specific molecular signal necessary to bring about the formation of a desired cell. Not all of these molecular signals are chemicals which can easily be introduced into the cultured petri dishes where embryonic stem cell lines reside. Instead, many are structural or mechanical factors specifically found in the intricate environment of a naturally growing embryo. Currently, experimental scientists are not able to reproduce all of these factors, such as mechanical tension or electric fields, in a petri dish.2 According to Dr. David Anderson, a noted stem cell researcher,

“What seems lost in the current debates [about stem cell research] is a sense of how difficult it really is, in practice, to get stem cells to do what you want them to.”4

It is very possible that even with “patience, dedication, and financing to support the work, we will never be able to replicate in a culture dish the nonmolecular factors necessary to get embryonic stem cells to do what we want them to.”2 Condic goes on to point out that failure to replicate all of the factors necessary for proper embryonic stem cell differentiation could lead to the development of cells which appear normal (based on the limited knowledge scientists have of exactly what a “normal” cell is) and are used for treatment, but turn out to be quite abnormal, lead to potentially serious side effects later on, and leave the patient in worse shape than before the treatment. The final scientific problem with using human embryonic stem cells is based on sound and accepted scientific practice: there simply has not been enough evidence gathered from experiments with animals to justify attempting similar procedures with humans. According to Condic,

“To date there is no evidence that cells generated from embryonic stem cells can be safely transplanted back into adult animals to restore the function of damaged or diseased adult tissues.”

Until such evidence is produced based on experiments with animals, it goes against common scientific and medical practice to go ahead and begin experiments on human beings (or in this case, with human embryos).2

The argument in favor of embryonic stem cell research is also weakened by the promise of what is considered by many to be a scientifically less risky and ethically less controversial alternative: adult stem cell research. Though the study of adult stem cells is not as advanced as that of embryonic stem cells, scientists have made much progress with them in the past few years. Adult stem cells can be taken from patient biopsies, grown in culture and made to develop into a wide variety of mature types of cells. Using adult stem cells would completely bypass the immunological problems caused by the use of embryonic stem cells; since the adult stem cells would actually come from the patient, there would be no issue of “matching” the stem cells to the patient. The main concern with using adult stem cells is that scientists don’t know just how many different mature cell types a single adult stem cell population can generate.2 Dr. Anderson observes,

“Some experiments suggest these [adult] stem cells have the potential to make mid-career switches, given the right environment, but in most cases this is far from conclusive.”4

This characteristic is not unique to adult stem cells however. As was already noted, it is extremely difficult to induce even embryonic stem cells to follow the “career path” that you would like them to. In fact, in this regard, adult stem cells have an advantage: whereas embryonic stem cells must be fully converted into the desired specialized cell before it could be used for treatment, an adult stem cell is already partially specialized. Therefore, with an adult stem cell, there are fewer genetic buttons to push before it becomes what you want. And when it comes to medical utility, the “limits” of adult stem cells are largely irrelevant. As Condic points out, “If a patient with heart disease can be cured using adult cardiac stem cells, the fact that these “heart-restricted” stem cells do not generate kidneys is not a problem for the patient.”2

Virtually all of the debate on the ethics of embryonic stem cell research centers around the same question that makes abortion such an inflammatory issue: at what point does a person actually become a person? Supporters of embryonic stem cell research believe that such research is absolutely essential, because it could potentially help millions without hurting anyone, since to them, a human embryo (or at least a human embryo growing outside of the mother’s womb) is not a person, but simply a living, growing mass of tissues. Those opposed to embryonic stem cell research on moral or ethical grounds believe that no potential medical benefit can justify the destruction of human embryos, an act which, to them, would constitute murder, since they consider a human embryo to be a person.1

Those in favor of embryonic stem cell research are agreed that the embryos from which embryonic stem cells are derived are not people, but they disagree at what point personhood is actually achieved. Some say that a fetus becomes an actual person at the point that it is capable of living outside of the mother’s womb,5 but this definition seems unacceptable, since the age at which an infant can live outside the mother is directly related to medical capabilities. With the great medical advancement in being able to care for premature babies, by this argument, fetuses become people at an earlier age now than they did a hundred years ago, when a baby born weeks early was sure to die. And in the same sense, personhood is achieved in the United States earlier than in third-world countries because here we have the medical technology to care for premature babies. Surely the argument that a fetus become a person when it is capable of living without the mother is a weak one. Indeed, even after a baby is born, and no longer needs the protection of the mother’s womb, it still is utterly helpless, and needs complete care, so one could argue that as a newborn infant, or even as a small child, personhood is not achieved because it is still dependent on the care of others. Others say that a human embryo does constitute a person, but only if it resides in the mother’s womb, where it has the ability to mature into a fetus and eventually into a newborn baby, and that the embryos which are used in stem cell research, since they will never be implanted and consequently grow into babies, are not people.5 Condic argues that this view is also unacceptable, because it equates developmental ability with human life and worth. In Western culture, basic human rights are not parceled out on the basis of performance or ability, and Condic points out that

“Unless we are willing to assign personhood proportionate to ability (young children, for example, might only be 20 percent human, while people with myopia, 95 percent), the limited abilities of prenatal humans are irrelevant to their status of human beings.”5

The eminent ethicist Dr. Joseph Fletcher proposes a “profile of man” which lists twenty characteristics that one must possess in order to be human including a minimum intelligence, the capability to relate to others, and the ability to communicate.6 The problems with this view are obvious and numerous: is one person less human than another because he is not as smart, or because he has trouble forming relationships with others? Was Hellen Keller, a source of admiration and inspiration for millions, subhuman before she learned how to communicate? Such a profile seems entirely subjective and insufficient to determine one’s personhood. Some argue from a Biblical standpoint that a person’s life begins at birth. Genesis 2.7 says, “Then the Lord God formed man of dust from the ground, and breathed into his nostrils the breath of life; and man became a living being.” Some suggest that this verse implies that a person’s life begins at birth, when he draws his first breath. However, the word translated “breath of life” in this verse is the Hebrew word nephesh, a word which is usually translated “soul” or “life.”7 Besides, Adam was a special case, and can’t always be used to infer general principles of human life. After all, the Bible indicates that Adam was never a baby at all, but that he was full-grown when created.

Those opposed to embryonic stem cell research on ethical grounds believe that human embryos are essentially people, and support this view in a number of ways. Condic believes that the definition of life is both scientific and objective, and suggests that we can determine when a person’s life begins by observing when it ends. According to Condic,

“Death occurs when the body ceases to act in a coordinated manner to support the continued healthy functions of all bodily organs.”

Life doesn’t end when a person stops breathing, or the heart stops beating, as science has now given us the ability to resuscitate people at times, or when every last cell has ceased to live, as cellular life may continue for some time following the cessation of the body’s ability to act as an integrated whole. So, what does the nature of death tell us about the beginning of life? According to Condic,

“From the earliest stages of development, human embryos clearly function as organisms. Embryos are not merely collections of human cells, but living creatures with all the properties that define any organism as distinct from a group of cells; embryos are capable of growing, maturing, maintaining a physiologic balance between various organ systems, adapting to changing circumstances, and repairing injury. Mere groups of human cells do nothing like this under any circumstances.”5

There are also numerous Biblical passages that suggest that a person’s life begins at conception. First, in Jeremiah 1.5, God says to Jeremiah, “Before I formed you in the womb I knew you, and before you were born I consecrated you; I have appointed you a prophet to the nations.” This passage implies that Jeremiah was a person whom God had already singled out for a specific purpose even before he was born. A second argument comes from the book of Luke, when Mary, pregnant with the baby Jesus, goes to visit Elizabeth, who is pregnant with John the Baptist. In Luke 1.44, Elizabeth, speaking to Mary, says, “…When the sound of your greeting reached my ears, the baby leaped in my womb for joy.” That the unborn John the Baptist was able to recognize the unborn Jesus indicates that the power of the Holy Spirit was involved, but also indicates that both were already people, and not merely large collections of cells awaiting the receipt of personhood upon birth. Also, the Bible makes no distinction in terms when referring to a baby before and after birth: the word translated “baby” in this passage is the Greek word brephos, a word used in the Bible to refer to unborn infants, newborn babies, and young children alike.7 Finally, James 2.26 states that “…the body without the spirit is dead….” If the body is dead without the spirit, then it follows that the body must have the spirit in order for it to be alive. There is no argument as to whether or not an unborn fetus is alive; that is universally accepted. The argument comes over whether or not a living fetus is a person. But, since an unborn fetus is alive, according to the Bible it must have a spirit. And since it is alive and has a spirit, how can we deny that it is a person?

The arguments that suggest that personhood begins at conception are more objective and convincing than those which suggest that it begins at any other time, and therefore, human embryos should be considered to be fully human and not destroyed during research, no matter how beneficial the research might potentially be. The more time that is spent in the area of adult stem cell research, the more it appears to be a very promising field of study, one which could potentially provide the same benefits which science is hoping to achieve from embryonic stem cell research, without the destruction of a single human life.